The invention relates to improvements in charging valves which pass a controlled predetermined amount of material from a supply to a working machine requiring the amount of material. More particularly, the invention relates to a bucket wheel charging valve having parallel alternately rotatable wheels each with cells or pockets on the periphery thereof.
Passing a valved charge to a work machine such as a comminution machine having a flow through of hot gasses with the materials is accomplished with the use of a bucket wheel or a double oscillating charging valve. Double oscillating valves are very disadvantageous because of the necessity of discontinuous operation, but also because of the necessity of low supply speed as the materials passing through the charging valve require a long release and dropping time. By comparison, bucket wheel charging valves which have heretofore been used make it possible to have a continuous operation, but difficulties are encountered with the adhesion of material onto the walls of the bucket which is particularly true when charging moist materials. Material depositing and adhering to the walls of the charging valves lead to a substantial decrease or to an undesirable alteration of the output quantity passed by the valve. Quantitatively controlled and uniform charging of a work machine with materials, particularly with moist or adherent materials has not been possible with valves heretofore used with the types of aggregates and material referred to.
It is accordingly an object of the present invention to provide an improved bucket wheel charging valve which makes possible the uniform charging of a work machine with materials, and particular moisture adhesive materials.
In accordance with a feature of the invention, the object is attained by providing a bucket wheel where the wheel has arcuate recesses in the periphery having the recesses or cells with their inner walls constructed on the arc of a circle. The bucket wheels are rotated alternately with each alternately driven at a prescribed angle of rotation which is equal to the width of the particular cell or recess of the other wheel. The bucket wheels are also arranged to be spaced from each other so that the outer rim end of the spoke between the recesses passes in close running or cleaning relationship to the wall of the recess of the opposite bucket wheel. The bucket wheel charging valve construction of the present invention includes an outer rim of spokes between each of the pockets so that the rim of the driven wheel slides along the inner wall of the arc shaped recess of the non-driven wheel and with the wheels driven alternately, there is a constant cleaning of each of the bucket walls. The buckets of the bucket wheels are maintained in operation and always kept free from adhering material. The bucket wheels are driven at a predetermined controlled arcuate rotation and at a controlled speed so that constant quantities of material are supplied to the work machine. The bucket wheel charging valve construction of the invention makes possible a constant uniform charging of the treatment or processing machine with materials, and particularly with moisture adhesive materials, and therefore, optimum control of the amount of material passed is attained over a long period of time which is not altered by the build-up of material to foul the valve and change its rate of delivery.
A further feature of the invention is that there is provided a drive for the bucket wheel charging valve including a crank with a connecting rod which connects to lever arms that are connected to a rotary drive on the axis of each of the bucket wheels and the crank drive continues in uniform rotation to drive the bucket wheels alternately in counter-rotation through a specific angle which includes the width of the cell formed on the periphery of the bucket wheel. The crank drive with its connecting rod connected to the lever arms are connected to a one-way rotary drive arranged on the axis of each of the bucket wheels so that they are alternately rotated through a specific angle of rotation.
A further feature of the invention is the provision of a rotary drive for each of the bucket wheels in the form of a free wheeling or a gripping clutch roller drive arrangement or a pawl drive ratchet arrangement.
Other advantages, objects and features, as well as equivalent structures which are intended to be covered herein, will become more apparent with the teaching of the principles of the invention in connection with the disclosure of the preferred embodiments in the specification, claims and drawings, in which: